Foreign nationals who intend to engage in employment in the Philippines are required to secure permission from the Department of Labor and Employment (DOLE), subject to certain exemptions and exclusions.

In the case of a non-resident alien, the employment permit may only be issued after a determination of the non-availability of a person in the Philippines who is competent, able and willing at the time of application to perform the services for which the alien is desired.

Source:
http://www.ble.dole.gov.ph/downloads/AEP/AEP_Q&A.pdf
http://www.ble.dole.gov.ph/downloads/issuances/DO%20186-17%20Revised%20Rules%20For.pdf